Question

isotopes become unstable when...
the attraction of protons for neutrons is equal. the electrons are greater than protons.
there are more protons than electrons. there is a wide gap between protons and neutrons

Explanation:

Isotopes are atoms of the same element with different numbers of neutrons. The stability of an isotope depends on the balance between protons and neutrons in the nucleus. When there is a wide gap between the number of protons and neutrons, the nucleus becomes unstable. This is because the strong nuclear force, which holds protons and neutrons together, cannot effectively counteract the electrostatic repulsion between protons if the neutron - proton ratio is too high or too low.

• Option 1: If the attraction of protons for neutrons is equal, it does not imply instability. In fact, a proper balance (not necessarily equal in number in most cases) is what is needed for stability.
• Option 2: The number of electrons compared to protons affects the charge of the atom (ion formation), not the nuclear stability of isotopes.
• Option 3: The number of protons compared to electrons affects the charge of the atom (ion formation), not the nuclear stability of isotopes.
• Option 4: A wide gap between protons and neutrons disrupts the balance in the nucleus, leading to instability.

Answer:

the attraction of protons for neutrons is equal.